1. Field of Invention
The present invention relates to the field of data management, and in particular to a flexible ontology data import/export method and apparatus which can import/export ontologies from known standard formats to private formats and enable an ontology management system to be applied to more applications.
2. Description of Prior Art
Ontology is one of the important data semantic representation methods, and the aim of ontology data management is to enable an application to make better use of ontology data so as to achieve an intelligent level. The import and export of ontology data are significant functions in an ontology data management, the function of importing can store ontology data from different sources into an ontology management system, and the function of exporting can represent ontology data in the ontology management system with various formats for use by different applications.
Ontology information can be organized as a plurality of forms including standard formats recognized in the industry, corporate-inside formats used widely within a corporate as well as private formats utilized in certain applications.
The difficult and crucial problems to be solved in the current ontology data management are how to handle the import of an unknown private format in terms of ontology import, and how to export a private format based on different conditions in terms of ontology export.
Currently, there have been some efforts and methods related to ontology import/export.
For example, the system in a first example can import ontologies in known format, and export ontology data congruous to a query condition according to XQL (XML Query Language), and the exported format is also a fixed known format.
FIG. 12 shows the overall operation flow in the first example, where the format acceptable to the system is fixed as Known Format 1, the exported format is also fixed as Known Format 2, and the format determiner of the system decides whether the input format is Format 1 and plainly rejects the import if the answer is NO. As to the export, the system supports complete export under no condition as well as export based on query language. Since the ontology representation language is XML in the system, an XML database is employed to store ontologies, and XQL is used as export language.
Meanwhile, the system in a second example can import ontologies in a fixed format 1 and export ontologies in a fixed format 2, while the ontology is not stored, and the import and export are completed in one pipeline.
The method proposed in JP 10-333952 can separate automatically with a separator the data inside some application into data formed as a table or a list, and then export these data to other applications for further use.
Further, the method in JP 08-190479 performs data conversion based on value range and length of database column type during database conversion, and decides the correspondence between the columns of conversion source and destination.
In summary, the existing methods of ontology import/export can import/export ontologies in fixed known formats, and export ontology data conforming to query conditions based on query language at the time of export. The following problems, however, have not been overcome.    (1) Ontologies in any unknown private format cannot be imported. Importing ontologies in any private unknown format include data separation and determination of property value range and type, while the current methods can handle only data separation and have no ability to determine property value range and type.    (2) It is impossible to export ontologies in any known and unknown format according to search condition for a keyword.    (3) It is impossible to export ontologies in any known and unknown format in the manner of the combination of keywords and query language.
The import/export methods based on text and database can execute format conversion according to data type, while text and database differ considerably from ontology data in that the former is a data carrier, and in the latter there exist concepts, properties and instances, the conversion of which should be considered respectively during the conversion of ontology data. Therefore, remarkable change needs to be made to the data conversion method based on text and database when this method is applied to ontology import.